The invention relates to a magnetic-tape cassette comprising: a housing having first and second major walls which are parallel to one another, two side walls, a rear wall, an opening at the front which extends back into the first major wall, and a partition which separates this front opening from the interior of the housing; two reel hubs supported between the major walls so as to be rotatable about axes which extend perpendicularly to the major walls, the first major wall having two openings through which the drive spindles of a magnetic-tape-cassette apparatus can be coupled to the reel hubs, and a magnetic tape wound around the reel hubs with a part of the tape extending across the front opening; a front cover movable between closed and open positions and comprising a main portion which in the closed position of the front cover covers the front opening and the part of the magnetic tape which extends across the front opening, and side flanges which are situated one adjacent each side wall of the housing and which are pivotally connected to said side walls; and a sliding plate which is situated on the outside of the housing and which comprises a main portion which is situated adjacent the first major wall of the housing, the sliding plate being slidably guided on the housing for movement parallel to the first major wall towards the rear wall, from a closed position in which it latches the front cover in the closed position and in which the main portion of the sliding plate covers the front opening where this opening extends back into the first major wall, to an open position to unlatch the front cover and to give access to the front opening for the passage thereinto of tape-withdrawal means of a magnetic-tape-cassette apparatus.
Such a magnetic-tape cassette is disclosed in U.S. Pat. No. 4,235,395. This known cassette, which is referred as a V-2000 cassette, has a front opening which is covered by the front cover at the front and by a sliding plate at the sides of the two major walls. In the closed position of the front cover and the sliding plate the cassette is thus protected against the penetration of dirt and against mechanical damage, which may be particularly detrimental to the taut part of the magnetic tape which extends across the front opening. In the closed position the sliding plate also constitutes a latch for the front cover, so that the front cover cannot be opened inadvertently while the cassette is being handled by the user. However, since the sliding plates can be displaced freely from the closed position towards the rear, it may happen that the front cover is accidentally swung open by the user after the sliding plate has been slid rearwards, so that the part of the magnetic tape which extends across the front opening may be damaged. Furthermore, dirt may penetrate the interior of the cassette housing because under specific conditions the interior of the known cassette is not perfectly sealed at the location of the openings in the two major walls.